On a line with the tumblers, or better still, on a small 

 slightly-raised shelf behind them, should be placed several 

 small bottles containing the fluids ordinarily used for 

 staining "bacteria. There are now several bottles used 

 especially for this purpose, some being furnished with 

 pipettes of different forms, with other means for 

 transferring the stain to the cover-glass. Any small 

 (2-ounce), firmly-standing bottle, however, through the 

 cork of which passes a glass tube drawn out below, an- 

 swers every demand. For ordinary work there should 

 be five such bottles, each filled with one of the following 

 staining fluids: Methylene-blue, Gentian-violet, Puchsin, 

 Ziehl's carbol-fuchsin solution and Gabbet's solution. 

 Although the latter often fails to stain well, it neverthe- 

 less is an excellent decolorizer, and in the hands of an 

 expert is admirable for making a rapid diagnosis of tuber- 

 culous sputum. To these stains may be added any other 

 desired stain, such as Bismarck-brown, LoefBer's solution, 

 etc. The usual staining fluids (Methylene-blue, Gentian- 

 violet, Fuchsin) prepared as under I (foot-note 2 a) will not 

 only give excellent staining results, but will also keep in- 

 definitely. 



Upon the desk there should also be a small bottle of 

 cedar-oil, from which a small drop may quickly be trans- 

 ferred to the slide without necessitating the use of more 

 than one hand. Within easy reach may be hung a bunch 

 of filter-papers cut into strips, say 1.5 inches broad by 6 

 inches long. On a shelf above the desk may be placed 

 a large bottle of distilled water, from which a 

 rubber tube descends close to the hand ; the tube 

 is closed near its lower end with a Mohr pinch- 

 cock (Fig. 1). This is an exceedingly convenient 

 arrangement also for the corrosive-sublimate 

 Fig. 1. bottle. The desk is now in readiness, and should 

 always be so for ordinary work, which must necessarily 

 be much accelerated since everything that is desired is 

 within reach. 



If there is any one thing the bacteriologist has to do 

 more than another it is perhaps to make cover-glass prep- 

 arations, especially if he is working upon any special or- 

 ganism. Although it may seem a simple matter to make 

 such preparations, anyone who has had charge of students 

 knows some of the difficulties to be surmounted — that is, 

 if their results can be taken as criteria. Indeed, it is by 

 no means so seldom that men of experience have difficulty 



in preparing what might be considered worthy specimens. 



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